NRefactory 5 had a lot of analyzers and refactorings that we wanted to bring forward, and we did so in the NR6Pack. It was initially tied very tightly to NRefactory, and we had a shared project that copied code to both (at first it was straight linking). As we learned, we removed more and more ties and NR6Pack was finally independent from NRefactory. However, they still shared the same GitHub repository - making contributing unnecessarily hard (oh, and the repo was quite big because the Web properties were also in there).

Thus, in Ischl we sat down together for name-finding because the initial "pack" was no longer correctly reflecting what was in the codebase: the refactorings had taken center stage. With that in mind, it didn't take us long to settle on a new name - and so 5/30/2015 marked the last release that used the old name (we still wanted a stable release before doing renaming, and, once again, a restructuring).

One thing before closing: although we use the suffix "for Visual Studio", the refactoring/analyzer library itself is a portable class library (PCL). Yes, it is cross platform, and not only for fun: it is used in MonoDevelop today (remember: Refactoring Essentials is a part of our NRefactory 6 effort).